The present invention relates to a digital to analog converter (hereinafter abbreviated as DAC).
At present, owing to the progress in the integrated circuit technology, DACs having a resolution of 8 to 10 bits have become to be mass-produced stably with a high reliability.
However, mutual matching capabilities between the elements produced by the integrated circuit technology have been inherently limited, and hence it has been very difficult to realize a DAC having a high resolution. For instance, in order to realize a high resolution DAC of 12 to 16 bits it is necessary either to employ a method for constructing of discrete parts in which resistor elements having a good matching capability are independently used or to employ a method for fine adjustment relying upon function trimming by making use of a laser beam, and therefore, not only the manufacturing cost has been very high, but also the reliability of the elements has been lowered.